The invention concerns a process for the production of components involved in the installation of blades in hydrodynamic machines and for components made by said process.
Hydrodynamic systems encompass at least torque converters and abrasion free auxiliary brake apparatuses, the latter being also known as xe2x80x9cretardersxe2x80x9d. These elements function in vehicle transmissions and vehicle drive trains. In said hydraulic systems, components are employed, which are equipped with a multiplicity of blades, in order to coact with the applied hydrodynamic fluids. The manufacture of these bladed components has been developed either on a basis of high functionality or on the basis of the greatest possible savings in cost.
Up to the present time, because of the lack of an optimized manufacturing technology, a conflict as to which goal is to be sought has arisen between the two named principles
EP 07 32 519 A1, for instance, discloses a hydrodynamic retarder having a base body in which recesses have been machined for the positioning of the blades. The blades are to be inserted into the said recesses and subsequently affixed therein by welding or brazing, for example, and thus made integral with the said base body. A shape-fit connection for the transmission of the forces is carried out only under limited circumstances. Because of the high specific loadings, which can arise in retarder operation by cavitation, for example, this shape-fit method carries corresponding risks.
The invention has the purpose of disclosing a manufacturing process which is economic in nature and assures a reliable functionality of the components.
In accord with the invention, a process for the manufacture of components in hydrodynamic machines is proposed, wherein the hydrodynamic machines possess a blading which is constructed by blades which are to be bound to a base body. The blades are bound to the base body by shape-fitting, in a metal shaping process actuated by a continuously rotating pressure roller and a continuously applied pressure. In an advantageous embodiment of the invention, the base body, which is a prefabricated torus, is pressed by the pressure roller against the blades, while the blades are held against the pressure of the pressure roller by a holding apparatus. In one embodiment of the process, the pressure roller acts upon the base body on that side of the base body which is placed remote from the blades. In yet another embodiment, the pressure roller runs along the base body at right angles to the outer contour of a device in which the blades are held. Another embodiment shows, that the pressure roller is run counter to its direction of rotation along the base body, in order to press the material of the base body into the recesses between the blades for the formation of a shape-fit. In another advantageous embodiment, the blades held in a holding device are pressed against an outer contour, which corresponds to the contour of the blades, in order to maintain a constant shape of the blades when they are subjected to the pressure of the pressure roller. One embodiment exhibits a preshaped base body which, when subjected to the pressure of the pressure roller upon simultaneous creation of a shape-fit with the blades, obtains its final shape corresponding to the outer contour of the device.
In an advantageous embodiment example, there is a different wall thickness for the blades and/or the base body in their longitudinal length and/or in their width. By means of the application of a pressure roller, components can also be worked, which do not have a uniformly remaining wall thickness, so that the wall thickness can be set at a value for optimal functionality. The base body can be made of various construction materials.
One embodiment has a base body of a malleable aluminum alloy. Advantageously the hydrodynamic machine can be operated as a torque-converter for a vehicle transmission. It can also be operated as a hydrodynamic retarder, which latter supports the vehicle as an auxiliary to friction operated brakes during slowing of the vehicle, especially along long stretches of a downward grade.